Boundary Condition Nomenclature Confusion in Groundwater Flow Modeling

Jazayeri, Amir; Werner, Adrian D.

doi:10.1111/gwat.12893

Cited by 12 publications

(18 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sea was incorporated as a Robin boundary condition (Jazayeri & Werner, 2019), which calculates the mass flux across the boundary ( Q bnd ) as follows (Guo & Langevin, 2002):

\begin{array}{l} left & Q_{bnd} = ρ_{up} Cond (h_{f, bnd} - h_{f, cell}) \end{array}

where ρ up is the density upstream of the flow, so the density of the model cell with outward flow and the density of the sea with inward flow; Cond is the conductance of the boundary; and h f ,bnd and h f ,cell are the fresh water heads (Guo & Langevin, 2002; Langevin et al., 2003; Post et al., 2007) of, respectively, the boundary and model cell. We used the median eustatic sea level curve of the last 45 ka (Spratt & Lisiecki, 2016) to set the heads at the sea boundary.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Factors Determining the Natural Fresh‐Salt Groundwater Distribution in Deltas

Engelen

Bierkens

Delsman

et al. 2021

Water Resources Research

View full text Add to dashboard Cite

River deltas are of high socioeconomic value, since they are often densely populated areas with high agricultural productivity (Neumann et al., 2015; Seto, 2011). The combination of growing population, increasingly intensive agriculture, and, in some areas, increased likelihood of droughts is expected to lead to fresh water shortages in surface water systems (Bucx et al., 2010). These stresses in turn will instigate more groundwater pumping, which leads to sea water intrusion and the upconing of saline groundwater (Michael et al., 2017; Werner et al., 2013). Despite that salinization poses a big problem to many large deltas (Rahman et al., 2019), the volume of fresh groundwater resources in many deltas is unknown, especially in the deeper parts of the groundwater system. While advances have been made in monitoring, especially with the onset of large-scale airborne electromagnetic (AEM) studies (King et al., 2018), 3D variable-density groundwater modeling still remains the only method to estimate a complete 3D fresh-salt groundwater distribution for large-scale groundwater systems (Faneca Sànchez et al., 2012). These models also have the added benefit

show abstract

“…The sea was incorporated as a Robin boundary condition (Jazayeri & Werner, 2019), which calculates the mass flux across the boundary ( Q bnd ) as follows (Guo & Langevin, 2002):

\begin{array}{l} left & Q_{bnd} = ρ_{up} Cond (h_{f, bnd} - h_{f, cell}) \end{array}

Section: Methodsmentioning

confidence: 99%

“…The sea was incorporated as a Robin boundary condition (Jazayeri & Werner, 2019), which calculates the mass flux across the boundary (Q bnd ) as follows (Guo & Langevin, 2002):…”

Section: Offshorementioning

confidence: 99%

Factors Determining the Natural Fresh‐Salt Groundwater Distribution in Deltas

Engelen

Bierkens

Delsman

et al. 2021

Water Resources Research

View full text Add to dashboard Cite

show abstract

“…Despite the large groundwater volume of the NDA, the amount of groundwater suitable for domestic, agricultural, or industrial water supply is limited. A considerable fraction of the groundwater volume is saline (Kashef, 1983;Sefelnasr and Sherif, 2014) or even hypersaline and unsuitable for most uses. Saline groundwater can be detrimental to Egypt's already critical food supply.…”

Section: Area Relevance and Vulnerabilitymentioning

confidence: 99%

“…Hydrogeological research dealing with this area generally assumed that the connection between aquifer and sea is completely open (e.g. Kashef, 1983;Mabrouk et al, 2018;Sefelnasr and Sherif, 2014;Sherif et al, 1988), but there exists ample evidence against this assumption from both seismics (Abdel-Fattah, 2014;Abdel Aal et al, 2000;Samuel et al, 2003) as well as from the fact that offshore borelogs contain more clay than sands (Salem et al, 2016). These observations can be explained by the fact that the fraction of marine clays in deltas generally increases seawards (Nichols, 2009).…”

Section: Hydrogeologymentioning

confidence: 99%

See 1 more Smart Citation

A three-dimensional palaeohydrogeological reconstruction of the groundwater salinity distribution in the Nile Delta Aquifer

Engelen

Verkaik

King

et al. 2019

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Holocene marine transgressions are often put forward to explain observed groundwater salinities that extend far inland in deltas. This hypothesis was also proposed in the literature to explain the large land-inward extent of saline groundwater in the Nile Delta. The groundwater models previously built for the area used very large dispersivities to reconstruct this saline and brackish groundwater zone. However, this approach cannot explain the observed freshening of this zone. Here, we investigated the physical plausibility of the Holocene-transgression hypothesis to explain observed salinities by conducting a palaeohydrogeological reconstruction of groundwater salinity for the last 32 ka with a complex 3-D variable-density groundwater flow model, using a state-of-the-art version of the SEAWAT computer code that allows for parallel computation. Several scenarios with different lithologies and hypersaline groundwater provenances were simulated, of which five were selected that showed the best match with the observations. Amongst these selections, total freshwater volumes varied strongly, ranging from 1526 to 2659 km 3 , mainly due to uncertainties in the lithology offshore and at larger depths. This range is smaller (1511-1989 km 3 ) when we only consider the volumes of onshore fresh groundwater within 300 m depth. In all five selected scenarios the total volume of hypersaline groundwater exceeded that of seawater. We also show that during the last 32 ka, total freshwater volumes significantly declined, with a factor ranging from 2 to 5, due to the rising sea level. Furthermore, the time period required to reach a steady state under current boundary conditions exceeded 5.5 ka for all scenarios. Finally, under highly permeable conditions the marine transgression simulated with the palaeohydrogeological reconstruction led to a steeper fresh-salt interface compared to its steady-state equivalent, while low-permeable clay layers allowed for the preservation of fresh groundwater volumes. This shows that long-term transient simulations are needed when estimating present-day fresh-salt groundwater distributions in large deltas. The insights of this study are also applicable to other major deltaic areas, since many also experienced a Holocene marine transgression.

show abstract

A numerical model of groundwater flow in Karewa-Alluvium aquifers of NW Indian Himalayan Region

Raazia

Dar

2021

Model. Earth Syst. Environ.

View full text Add to dashboard Cite

Boundary Condition Nomenclature Confusion in Groundwater Flow Modeling

Cited by 12 publications

References 21 publications

Factors Determining the Natural Fresh‐Salt Groundwater Distribution in Deltas

Factors Determining the Natural Fresh‐Salt Groundwater Distribution in Deltas

A three-dimensional palaeohydrogeological reconstruction of the groundwater salinity distribution in the Nile Delta Aquifer

A numerical model of groundwater flow in Karewa-Alluvium aquifers of NW Indian Himalayan Region

Contact Info

Product

Resources

About